Aperture Photometry Tool (APT)
Purpose: User-friendly, graphical-user-interface software for viewing FITS
files and performing aperture photometry.
Author: Russ Laher (SSC)
Date Contributed: 17 Apr 2012
System Requirements: Java
Information and Download
APT home page
Download APT
APT documentation
Aperture Photometry Tool (APT) is software for astronomers and
students interested in manually exploring the photometric qualities
of astronomical images. It is a graphical user interface (GUI)
designed to allow the image data associated with aperture
photometry calculations for point and extended sources to be
visualized, and, therefore, more effectively analyzed. The finely
tuned layout of the GUI, along with judicious use of color coding
and alerting, is intended to give maximal user utility and
convenience. Simply mouse-clicking on a source in the displayed
image will instantly draw a circular or elliptical aperture and sky
annulus around the source, and compute the source intensity and
its uncertainty, along with several commonly used measures of the
local sky background and its variability. The results are displayed
and can be optionally saved to an aperture-photometry-table file
and plotted on graphs in various ways using functions available
in the software. APT is geared toward processing sources in a
small number of images, and is not suitable for bulk processing
a large number of images, unlike other aperture photometry
packages (e.g., SExtractor). However, APT does have a convenient
source-list tool that enables calculations for a large number of
detections in a given image. The source-list tool can be run
either in automatic mode to generate an aperture photometry
table quickly, or in manual mode to permit inspection and
adjustment of the calculation for each individual detection.
APT displays a variety of useful graphs with just the push of a
button, including image histogram, x and y aperture slices,
source scatter plot, sky scatter plot, sky histogram, radial profile,
curve of growth, and aperture-photometry-table scatter plots and
histograms. APT has many functions for customizing the
calculations, including outlier rejection, pixel "picking" and
"zapping", and a selection of source and sky models. The
radial-profile-interpolation source model, which is accessed via the
radial-profile-plot panel, allows recovery of source intensity from
pixels with missing data, and can be especially beneficial in
crowded fields.
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